The present invention relates to preceding vehicle following control technique for controlling an actual vehicle spacing or distance to a preceding vehicle and a vehicle speed, and specifically to control technique for controlling the actual vehicle spacing to a desired spacing in the presence of a captured preceding vehicle ahead and controlling the actual vehicle speed to a desired vehicle speed in the absence of a captured preceding vehicle.
A Japanese Patent Kokai Publication H8(1996)175221 shows a constant speed travel control system associated with an antilock brake control system.
If a preceding vehicle following control system employs a strategy of canceling a constant speed travel mode in response to a depression of a brake pedal, resuming the constant speed travel mode normally upon release of the brake pedal, and preventing a return to the constant speed travel mode even after a release of the brake pedal when the anti-lock brake system become active, there arises a problem in the case of an automatic inching operation for controlling the vehicle spacing until the vehicle speed is reduced to zero. If, after a start of the anti-lock brake control operation, a preceding vehicle slackens its deceleration in a vehicle speed region close to stoppage, the controlled vehicle stops deceleration and hence the following control is canceled. Therefore, even if the preceding vehicle is decelerated again, an automatic braking operation is not effected, and a driver""s braking operation is needed in some cases.
It is therefore an objective of the present invention to provide preceding vehicle following control apparatus and/or process for continuing a deceleration control after activation of an anti-lock brake control, without need for driver""s intervention.
According to the present invention, a preceding vehicle following control apparatus for controlling a controlled vehicle comprises:
a vehicle speed sensor to sense an actual vehicle speed of the controlled vehicle;
a vehicle spacing sensor to sense an actual vehicle spacing from the controlled vehicle to a preceding vehicle;
a vehicle speed controller to vary the actual vehicle speed of the controlled vehicle in accordance with a desired vehicle speed;
an anti-lock brake controller to perform an anti-lock brake control for preventing wheel locking; and
a vehicle speed controller to determine the desired vehicle speed V* in accordance with the actual vehicle speed and the actual vehicle spacing, the controller comprising,
a following control section to perform a preceding vehicle following control by setting a desired vehicle spacing from the controlled vehicle to a preceding vehicle in accordance with the actual vehicle speed and actual vehicle spacing and determining the desired vehicle speed to bring actual vehicle spacing closer to the desired spacing,
a deceleration control section to perform a deceleration control determining the desired vehicle speed to decrease the actual vehicle speed of the controlled vehicle, and
a mode change control section to cancel the following control of the following control section and instead initiating the deceleration control of the deceleration control section in response to a start of the anti-lock brake control of the anti-lock brake control device.
According to another aspect of the present invention, a preceding vehicle following control apparatus comprises: first means for detecting an anti-lock brake control operation for preventing wheel locking of the controlled vehicle; second means for performing a preceding vehicle following control for reducing a deviation of a sensed actual vehicle spacing from the controlled vehicle to a preceding vehicle, from a desired vehicle spacing; third means for performing a deceleration control for automatically decelerating the controlled vehicle; and fourth means for starting the deceleration control when the anti-lock brake control is detected in the following control.
According to the present invention, a preceding vehicle following control process comprises: detecting an anti-lock brake control operation; performing a preceding vehicle following control when the anti-lock brake control operation is not detected; performing a deceleration control when the anti-lock brake control operation is detected; allowing the deceleration control when the sensed actual vehicle spacing is smaller than or equal to a predetermined spacing value.